If you want to control what's shown there, you probably want to use Views and/or Panels.

As mentioned by @yitznewton, you'll also need to look at some kind of explict access control - relying on people never guessing URLs is a technique that's going to fail pretty quickly. If you're using CCK then the features are already there, waiting for you to use them. Otherwise, have a search round on Drupal.org to see some of the options.